Leah may appear to be the loving mom and devoted wife on TV — but a friend says she’s been secretly seeing her ex boyfriend without her husband Corey knowing! And this isn’t the first time she’s cheated on him!

So much for Teen Mom 2 star Leah Messer calming down now that she married to Corey Simms and has two twin daughters — Aliannah and Aleeah. Despite appearing as the sweet and devoted mother and wife on TV, Leah’s secretly been seeing her ex boyfriend Seth George behind Corey’s back!

“She has definitely met up with Seth without telling Corey,” a friend of Leah’s tells In Touch. When with Seth, Leah “has fun and feels like a teenager again.”

Despite Leah telling Corey that things are over with Seth, “they still meet up” when her parent’s watch her one-year-old girls, her friend explains. This is Leah’s “wild streak.”

Leah seems to fall hard for guys like Seth, who has a criminal record for petty larceny and joy riding. “Cory is more of a family type, but Seth is not,” says the friend. “What Leah likes about him is that he parties.”

“She drinks — and when she parties, she parties,” continues the friend. Unlike Corey, “Seth is able to keep up with her.”

This isn’t the first time Leah has led a double life. Shortly after having her babies, Leah and Corey split up after she had a fling with her ex, Robbie Kidd. But after things fell off with Robbie, Leah started hooking up with Seth. And then she continued to see Seth even while she was trying to win Corey back.

“She was dating Seth last summer, when she was trying to get back together with Corey,” confirms the friend. Leah “never told Corey about Seth” at that time.

Now, Leah feels “trapped” in her new life. According to her friend, Seth offers her an escape from reality.

But, how long is she going to be able to keep up this facade? And when Corey finds out, will he be as willing to forgive her this second time around — now that they’re married?